No smoking? The downward trend in smoking you saw in the last exercise is good news for the health of babies, but will it ever stop?  a) Explain why you can’t use the linear model you created in...

No smoking? The downward trend in smoking you saw in the last exercise is good news for the health of babies, but will it ever stop?

 a) Explain why you can’t use the linear model you created in Exercise 22 to see when smoking during pregnancy will cease altogether.

 b) Create a model that could estimate the year in which the level of smoking would be 0%.

c) Comment on the reliability of such a prediction.